isci: unify request frame handlers

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / scsi / isci / remote_device.c

/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * BSD LICENSE
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include <scsi/sas.h>
#include "isci.h"
#include "port.h"
#include "remote_device.h"
#include "request.h"
#include "remote_node_context.h"
#include "scu_event_codes.h"
#include "task.h"

/**
 * isci_remote_device_change_state() - This function gets the status of the
 *    remote_device object.
 * @isci_device: This parameter points to the isci_remote_device object
 *
 * status of the object as a isci_status enum.
 */
void isci_remote_device_change_state(
        struct isci_remote_device *isci_device,
        enum isci_status status)
{
        unsigned long flags;

        spin_lock_irqsave(&isci_device->state_lock, flags);
        isci_device->status = status;
        spin_unlock_irqrestore(&isci_device->state_lock, flags);
}

/**
 * isci_remote_device_not_ready() - This function is called by the scic when
 *    the remote device is not ready. We mark the isci device as ready (not
 *    "ready_for_io") and signal the waiting proccess.
 * @isci_host: This parameter specifies the isci host object.
 * @isci_device: This parameter specifies the remote device
 *
 */
static void isci_remote_device_not_ready(struct isci_host *ihost,
                                  struct isci_remote_device *idev, u32 reason)
{
        dev_dbg(&ihost->pdev->dev,
                "%s: isci_device = %p\n", __func__, idev);

        if (reason == SCIC_REMOTE_DEVICE_NOT_READY_STOP_REQUESTED)
                isci_remote_device_change_state(idev, isci_stopping);
        else
                /* device ready is actually a "not ready for io" state. */
                isci_remote_device_change_state(idev, isci_ready);
}

/**
 * isci_remote_device_ready() - This function is called by the scic when the
 *    remote device is ready. We mark the isci device as ready and signal the
 *    waiting proccess.
 * @ihost: our valid isci_host
 * @idev: remote device
 *
 */
static void isci_remote_device_ready(struct isci_host *ihost, struct isci_remote_device *idev)
{
        dev_dbg(&ihost->pdev->dev,
                "%s: idev = %p\n", __func__, idev);

        isci_remote_device_change_state(idev, isci_ready_for_io);
        if (test_and_clear_bit(IDEV_START_PENDING, &idev->flags))
                wake_up(&ihost->eventq);
}

/* called once the remote node context is ready to be freed.
 * The remote device can now report that its stop operation is complete. none
 */
static void rnc_destruct_done(void *_dev)
{
        struct scic_sds_remote_device *sci_dev = _dev;

        BUG_ON(sci_dev->started_request_count != 0);
        sci_base_state_machine_change_state(&sci_dev->state_machine,
                                            SCI_BASE_REMOTE_DEVICE_STATE_STOPPED);
}

static enum sci_status scic_sds_remote_device_terminate_requests(struct scic_sds_remote_device *sci_dev)
{
        struct scic_sds_controller *scic = sci_dev->owning_port->owning_controller;
        u32 i, request_count = sci_dev->started_request_count;
        enum sci_status status  = SCI_SUCCESS;

        for (i = 0; i < SCI_MAX_IO_REQUESTS && i < request_count; i++) {
                struct scic_sds_request *sci_req;
                enum sci_status s;

                sci_req = scic->io_request_table[i];
                if (!sci_req || sci_req->target_device != sci_dev)
                        continue;
                s = scic_controller_terminate_request(scic, sci_dev, sci_req);
                if (s != SCI_SUCCESS)
                        status = s;
        }

        return status;
}

enum sci_status scic_remote_device_stop(struct scic_sds_remote_device *sci_dev,
                                        u32 timeout)
{
        struct sci_base_state_machine *sm = &sci_dev->state_machine;
        enum scic_sds_remote_device_states state = sm->current_state_id;

        switch (state) {
        case SCI_BASE_REMOTE_DEVICE_STATE_INITIAL:
        case SCI_BASE_REMOTE_DEVICE_STATE_FAILED:
        case SCI_BASE_REMOTE_DEVICE_STATE_FINAL:
        default:
                dev_warn(scirdev_to_dev(sci_dev), "%s: in wrong state: %d\n",
                         __func__, state);
                return SCI_FAILURE_INVALID_STATE;
        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPED:
                return SCI_SUCCESS;
        case SCI_BASE_REMOTE_DEVICE_STATE_STARTING:
                /* device not started so there had better be no requests */
                BUG_ON(sci_dev->started_request_count != 0);
                scic_sds_remote_node_context_destruct(&sci_dev->rnc,
                                                      rnc_destruct_done, sci_dev);
                /* Transition to the stopping state and wait for the
                 * remote node to complete being posted and invalidated.
                 */
                sci_base_state_machine_change_state(sm, SCI_BASE_REMOTE_DEVICE_STATE_STOPPING);
                return SCI_SUCCESS;
        case SCI_BASE_REMOTE_DEVICE_STATE_READY:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET:
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
                sci_base_state_machine_change_state(sm, SCI_BASE_REMOTE_DEVICE_STATE_STOPPING);
                if (sci_dev->started_request_count == 0) {
                        scic_sds_remote_node_context_destruct(&sci_dev->rnc,
                                                              rnc_destruct_done, sci_dev);
                        return SCI_SUCCESS;
                } else
                        return scic_sds_remote_device_terminate_requests(sci_dev);
                break;
        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPING:
                /* All requests should have been terminated, but if there is an
                 * attempt to stop a device already in the stopping state, then
                 * try again to terminate.
                 */
                return scic_sds_remote_device_terminate_requests(sci_dev);
        case SCI_BASE_REMOTE_DEVICE_STATE_RESETTING:
                sci_base_state_machine_change_state(sm, SCI_BASE_REMOTE_DEVICE_STATE_STOPPING);
                return SCI_SUCCESS;
        }
}

enum sci_status scic_remote_device_reset(struct scic_sds_remote_device *sci_dev)
{
        struct sci_base_state_machine *sm = &sci_dev->state_machine;
        enum scic_sds_remote_device_states state = sm->current_state_id;

        switch (state) {
        case SCI_BASE_REMOTE_DEVICE_STATE_INITIAL:
        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPED:
        case SCI_BASE_REMOTE_DEVICE_STATE_STARTING:
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPING:
        case SCI_BASE_REMOTE_DEVICE_STATE_FAILED:
        case SCI_BASE_REMOTE_DEVICE_STATE_RESETTING:
        case SCI_BASE_REMOTE_DEVICE_STATE_FINAL:
        default:
                dev_warn(scirdev_to_dev(sci_dev), "%s: in wrong state: %d\n",
                         __func__, state);
                return SCI_FAILURE_INVALID_STATE;
        case SCI_BASE_REMOTE_DEVICE_STATE_READY:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET:
                sci_base_state_machine_change_state(sm, SCI_BASE_REMOTE_DEVICE_STATE_RESETTING);
                return SCI_SUCCESS;
        }
}

enum sci_status scic_remote_device_reset_complete(struct scic_sds_remote_device *sci_dev)
{
        struct sci_base_state_machine *sm = &sci_dev->state_machine;
        enum scic_sds_remote_device_states state = sm->current_state_id;

        if (state != SCI_BASE_REMOTE_DEVICE_STATE_RESETTING) {
                dev_warn(scirdev_to_dev(sci_dev), "%s: in wrong state: %d\n",
                         __func__, state);
                return SCI_FAILURE_INVALID_STATE;
        }

        sci_base_state_machine_change_state(sm, SCI_BASE_REMOTE_DEVICE_STATE_READY);
        return SCI_SUCCESS;
}

enum sci_status scic_sds_remote_device_suspend(struct scic_sds_remote_device *sci_dev,
                                               u32 suspend_type)
{
        struct sci_base_state_machine *sm = &sci_dev->state_machine;
        enum scic_sds_remote_device_states state = sm->current_state_id;

        if (state != SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD) {
                dev_warn(scirdev_to_dev(sci_dev), "%s: in wrong state: %d\n",
                         __func__, state);
                return SCI_FAILURE_INVALID_STATE;
        }

        return scic_sds_remote_node_context_suspend(&sci_dev->rnc,
                                                    suspend_type, NULL, NULL);
}

enum sci_status scic_sds_remote_device_frame_handler(struct scic_sds_remote_device *sci_dev,
                                                     u32 frame_index)
{
        struct sci_base_state_machine *sm = &sci_dev->state_machine;
        enum scic_sds_remote_device_states state = sm->current_state_id;
        struct scic_sds_controller *scic = sci_dev->owning_port->owning_controller;
        enum sci_status status;

        switch (state) {
        case SCI_BASE_REMOTE_DEVICE_STATE_INITIAL:
        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPED:
        case SCI_BASE_REMOTE_DEVICE_STATE_STARTING:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
        case SCI_BASE_REMOTE_DEVICE_STATE_FINAL:
        default:
                dev_warn(scirdev_to_dev(sci_dev), "%s: in wrong state: %d\n",
                         __func__, state);
                /* Return the frame back to the controller */
                scic_sds_controller_release_frame(scic, frame_index);
                return SCI_FAILURE_INVALID_STATE;
        case SCI_BASE_REMOTE_DEVICE_STATE_READY:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET:
        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPING:
        case SCI_BASE_REMOTE_DEVICE_STATE_FAILED:
        case SCI_BASE_REMOTE_DEVICE_STATE_RESETTING: {
                struct scic_sds_request *sci_req;
                struct ssp_frame_hdr hdr;
                void *frame_header;
                ssize_t word_cnt;

                status = scic_sds_unsolicited_frame_control_get_header(&scic->uf_control,
                                                                       frame_index,
                                                                       &frame_header);
                if (status != SCI_SUCCESS)
                        return status;

                word_cnt = sizeof(hdr) / sizeof(u32);
                sci_swab32_cpy(&hdr, frame_header, word_cnt);

                sci_req = scic_request_by_tag(scic, be16_to_cpu(hdr.tag));
                if (sci_req && sci_req->target_device == sci_dev) {
                        /* The IO request is now in charge of releasing the frame */
                        status = scic_sds_io_request_frame_handler(sci_req, frame_index);
                } else {
                        /* We could not map this tag to a valid IO
                         * request Just toss the frame and continue
                         */
                        scic_sds_controller_release_frame(scic, frame_index);
                }
                break;
        }
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ: {
                struct dev_to_host_fis *hdr;

                status = scic_sds_unsolicited_frame_control_get_header(&scic->uf_control,
                                                                       frame_index,
                                                                       (void **)&hdr);
                if (status != SCI_SUCCESS)
                        return status;

                if (hdr->fis_type == FIS_SETDEVBITS &&
                    (hdr->status & ATA_ERR)) {
                        sci_dev->not_ready_reason = SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED;

                        /* TODO Check sactive and complete associated IO if any. */
                        sci_base_state_machine_change_state(sm, SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR);
                } else if (hdr->fis_type == FIS_REGD2H &&
                           (hdr->status & ATA_ERR)) {
                        /*
                         * Some devices return D2H FIS when an NCQ error is detected.
                         * Treat this like an SDB error FIS ready reason.
                         */
                        sci_dev->not_ready_reason = SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED;
                        sci_base_state_machine_change_state(&sci_dev->state_machine,
                                                            SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR);
                } else
                        status = SCI_FAILURE;

                scic_sds_controller_release_frame(scic, frame_index);
                break;
        }
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
                /* The device does not process any UF received from the hardware while
                 * in this state.  All unsolicited frames are forwarded to the io request
                 * object.
                 */
                status = scic_sds_io_request_frame_handler(sci_dev->working_request, frame_index);
                break;
        }

        return status;
}

static bool is_remote_device_ready(struct scic_sds_remote_device *sci_dev)
{

        struct sci_base_state_machine *sm = &sci_dev->state_machine;
        enum scic_sds_remote_device_states state = sm->current_state_id;

        switch (state) {
        case SCI_BASE_REMOTE_DEVICE_STATE_READY:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET:
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
                return true;
        default:
                return false;
        }
}

enum sci_status scic_sds_remote_device_event_handler(struct scic_sds_remote_device *sci_dev,
                                                     u32 event_code)
{
        struct sci_base_state_machine *sm = &sci_dev->state_machine;
        enum scic_sds_remote_device_states state = sm->current_state_id;
        enum sci_status status;

        switch (scu_get_event_type(event_code)) {
        case SCU_EVENT_TYPE_RNC_OPS_MISC:
        case SCU_EVENT_TYPE_RNC_SUSPEND_TX:
        case SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX:
                status = scic_sds_remote_node_context_event_handler(&sci_dev->rnc, event_code);
                break;
        case SCU_EVENT_TYPE_PTX_SCHEDULE_EVENT:
                if (scu_get_event_code(event_code) == SCU_EVENT_IT_NEXUS_TIMEOUT) {
                        status = SCI_SUCCESS;

                        /* Suspend the associated RNC */
                        scic_sds_remote_node_context_suspend(&sci_dev->rnc,
                                                              SCI_SOFTWARE_SUSPENSION,
                                                              NULL, NULL);

                        dev_dbg(scirdev_to_dev(sci_dev),
                                "%s: device: %p event code: %x: %s\n",
                                __func__, sci_dev, event_code,
                                is_remote_device_ready(sci_dev)
                                ? "I_T_Nexus_Timeout event"
                                : "I_T_Nexus_Timeout event in wrong state");

                        break;
                }
        /* Else, fall through and treat as unhandled... */
        default:
                dev_dbg(scirdev_to_dev(sci_dev),
                        "%s: device: %p event code: %x: %s\n",
                        __func__, sci_dev, event_code,
                        is_remote_device_ready(sci_dev)
                        ? "unexpected event"
                        : "unexpected event in wrong state");
                status = SCI_FAILURE_INVALID_STATE;
                break;
        }

        if (status != SCI_SUCCESS)
                return status;

        if (state == SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE) {

                /* We pick up suspension events to handle specifically to this
                 * state. We resume the RNC right away.
                 */
                if (scu_get_event_type(event_code) == SCU_EVENT_TYPE_RNC_SUSPEND_TX ||
                    scu_get_event_type(event_code) == SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX)
                        status = scic_sds_remote_node_context_resume(&sci_dev->rnc, NULL, NULL);
        }

        return status;
}

static void scic_sds_remote_device_start_request(struct scic_sds_remote_device *sci_dev,
                                                 struct scic_sds_request *sci_req,
                                                 enum sci_status status)
{
        struct scic_sds_port *sci_port = sci_dev->owning_port;

        /* cleanup requests that failed after starting on the port */
        if (status != SCI_SUCCESS)
                scic_sds_port_complete_io(sci_port, sci_dev, sci_req);
        else
                scic_sds_remote_device_increment_request_count(sci_dev);
}

enum sci_status scic_sds_remote_device_start_io(struct scic_sds_controller *scic,
                                                struct scic_sds_remote_device *sci_dev,
                                                struct scic_sds_request *sci_req)
{
        struct sci_base_state_machine *sm = &sci_dev->state_machine;
        enum scic_sds_remote_device_states state = sm->current_state_id;
        struct scic_sds_port *sci_port = sci_dev->owning_port;
        struct isci_request *ireq = sci_req_to_ireq(sci_req);
        enum sci_status status;

        switch (state) {
        case SCI_BASE_REMOTE_DEVICE_STATE_INITIAL:
        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPED:
        case SCI_BASE_REMOTE_DEVICE_STATE_STARTING:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR:
        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPING:
        case SCI_BASE_REMOTE_DEVICE_STATE_FAILED:
        case SCI_BASE_REMOTE_DEVICE_STATE_RESETTING:
        case SCI_BASE_REMOTE_DEVICE_STATE_FINAL:
        default:
                dev_warn(scirdev_to_dev(sci_dev), "%s: in wrong state: %d\n",
                         __func__, state);
                return SCI_FAILURE_INVALID_STATE;
        case SCI_BASE_REMOTE_DEVICE_STATE_READY:
                /* attempt to start an io request for this device object. The remote
                 * device object will issue the start request for the io and if
                 * successful it will start the request for the port object then
                 * increment its own request count.
                 */
                status = scic_sds_port_start_io(sci_port, sci_dev, sci_req);
                if (status != SCI_SUCCESS)
                        return status;

                status = scic_sds_remote_node_context_start_io(&sci_dev->rnc, sci_req);
                if (status != SCI_SUCCESS)
                        break;

                status = scic_sds_request_start(sci_req);
                break;
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE: {
                /* handle the start io operation for a sata device that is in
                 * the command idle state. - Evalute the type of IO request to
                 * be started - If its an NCQ request change to NCQ substate -
                 * If its any other command change to the CMD substate
                 *
                 * If this is a softreset we may want to have a different
                 * substate.
                 */
                enum scic_sds_remote_device_states new_state;
                struct sas_task *task = isci_request_access_task(ireq);

                status = scic_sds_port_start_io(sci_port, sci_dev, sci_req);
                if (status != SCI_SUCCESS)
                        return status;

                status = scic_sds_remote_node_context_start_io(&sci_dev->rnc, sci_req);
                if (status != SCI_SUCCESS)
                        break;

                status = scic_sds_request_start(sci_req);
                if (status != SCI_SUCCESS)
                        break;

                if (task->ata_task.use_ncq)
                        new_state = SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ;
                else {
                        sci_dev->working_request = sci_req;
                        new_state = SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD;
                }
                sci_base_state_machine_change_state(sm, new_state);
                break;
        }
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ: {
                struct sas_task *task = isci_request_access_task(ireq);

                if (task->ata_task.use_ncq) {
                        status = scic_sds_port_start_io(sci_port, sci_dev, sci_req);
                        if (status != SCI_SUCCESS)
                                return status;

                        status = scic_sds_remote_node_context_start_io(&sci_dev->rnc, sci_req);
                        if (status != SCI_SUCCESS)
                                break;

                        status = scic_sds_request_start(sci_req);
                } else
                        return SCI_FAILURE_INVALID_STATE;
                break;
        }
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET:
                return SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED;
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
                status = scic_sds_port_start_io(sci_port, sci_dev, sci_req);
                if (status != SCI_SUCCESS)
                        return status;

                status = scic_sds_remote_node_context_start_io(&sci_dev->rnc, sci_req);
                if (status != SCI_SUCCESS)
                        break;

                status = scic_sds_request_start(sci_req);
                if (status != SCI_SUCCESS)
                        break;

                sci_dev->working_request = sci_req;
                sci_base_state_machine_change_state(&sci_dev->state_machine,
                                                    SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD);
                break;
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
                /* device is already handling a command it can not accept new commands
                 * until this one is complete.
                 */
                return SCI_FAILURE_INVALID_STATE;
        }

        scic_sds_remote_device_start_request(sci_dev, sci_req, status);
        return status;
}

static enum sci_status common_complete_io(struct scic_sds_port *sci_port,
                                          struct scic_sds_remote_device *sci_dev,
                                          struct scic_sds_request *sci_req)
{
        enum sci_status status;

        status = scic_sds_request_complete(sci_req);
        if (status != SCI_SUCCESS)
                return status;

        status = scic_sds_port_complete_io(sci_port, sci_dev, sci_req);
        if (status != SCI_SUCCESS)
                return status;

        scic_sds_remote_device_decrement_request_count(sci_dev);
        return status;
}

enum sci_status scic_sds_remote_device_complete_io(struct scic_sds_controller *scic,
                                                   struct scic_sds_remote_device *sci_dev,
                                                   struct scic_sds_request *sci_req)
{
        struct sci_base_state_machine *sm = &sci_dev->state_machine;
        enum scic_sds_remote_device_states state = sm->current_state_id;
        struct scic_sds_port *sci_port = sci_dev->owning_port;
        enum sci_status status;

        switch (state) {
        case SCI_BASE_REMOTE_DEVICE_STATE_INITIAL:
        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPED:
        case SCI_BASE_REMOTE_DEVICE_STATE_STARTING:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
        case SCI_BASE_REMOTE_DEVICE_STATE_FAILED:
        case SCI_BASE_REMOTE_DEVICE_STATE_FINAL:
        default:
                dev_warn(scirdev_to_dev(sci_dev), "%s: in wrong state: %d\n",
                         __func__, state);
                return SCI_FAILURE_INVALID_STATE;
        case SCI_BASE_REMOTE_DEVICE_STATE_READY:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET:
        case SCI_BASE_REMOTE_DEVICE_STATE_RESETTING:
                status = common_complete_io(sci_port, sci_dev, sci_req);
                break;
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR:
                status = common_complete_io(sci_port, sci_dev, sci_req);
                if (status != SCI_SUCCESS)
                        break;

                if (sci_req->sci_status == SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED) {
                        /* This request causes hardware error, device needs to be Lun Reset.
                         * So here we force the state machine to IDLE state so the rest IOs
                         * can reach RNC state handler, these IOs will be completed by RNC with
                         * status of "DEVICE_RESET_REQUIRED", instead of "INVALID STATE".
                         */
                        sci_base_state_machine_change_state(sm, SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET);
                } else if (scic_sds_remote_device_get_request_count(sci_dev) == 0)
                        sci_base_state_machine_change_state(sm, SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE);
                break;
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
                status = common_complete_io(sci_port, sci_dev, sci_req);
                if (status != SCI_SUCCESS)
                        break;
                sci_base_state_machine_change_state(sm, SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE);
                break;
        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPING:
                status = common_complete_io(sci_port, sci_dev, sci_req);
                if (status != SCI_SUCCESS)
                        break;

                if (scic_sds_remote_device_get_request_count(sci_dev) == 0)
                        scic_sds_remote_node_context_destruct(&sci_dev->rnc,
                                                              rnc_destruct_done,
                                                              sci_dev);
                break;
        }

        if (status != SCI_SUCCESS)
                dev_err(scirdev_to_dev(sci_dev),
                        "%s: Port:0x%p Device:0x%p Request:0x%p Status:0x%x "
                        "could not complete\n", __func__, sci_port,
                        sci_dev, sci_req, status);

        return status;
}

static void scic_sds_remote_device_continue_request(void *dev)
{
        struct scic_sds_remote_device *sci_dev = dev;

        /* we need to check if this request is still valid to continue. */
        if (sci_dev->working_request)
                scic_controller_continue_io(sci_dev->working_request);
}

enum sci_status scic_sds_remote_device_start_task(struct scic_sds_controller *scic,
                                                  struct scic_sds_remote_device *sci_dev,
                                                  struct scic_sds_request *sci_req)
{
        struct sci_base_state_machine *sm = &sci_dev->state_machine;
        enum scic_sds_remote_device_states state = sm->current_state_id;
        struct scic_sds_port *sci_port = sci_dev->owning_port;
        enum sci_status status;

        switch (state) {
        case SCI_BASE_REMOTE_DEVICE_STATE_INITIAL:
        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPED:
        case SCI_BASE_REMOTE_DEVICE_STATE_STARTING:
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPING:
        case SCI_BASE_REMOTE_DEVICE_STATE_FAILED:
        case SCI_BASE_REMOTE_DEVICE_STATE_RESETTING:
        case SCI_BASE_REMOTE_DEVICE_STATE_FINAL:
        default:
                dev_warn(scirdev_to_dev(sci_dev), "%s: in wrong state: %d\n",
                         __func__, state);
                return SCI_FAILURE_INVALID_STATE;
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR:
        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET:
                status = scic_sds_port_start_io(sci_port, sci_dev, sci_req);
                if (status != SCI_SUCCESS)
                        return status;

                status = scic_sds_remote_node_context_start_task(&sci_dev->rnc, sci_req);
                if (status != SCI_SUCCESS)
                        goto out;

                status = scic_sds_request_start(sci_req);
                if (status != SCI_SUCCESS)
                        goto out;

                /* Note: If the remote device state is not IDLE this will
                 * replace the request that probably resulted in the task
                 * management request.
                 */
                sci_dev->working_request = sci_req;
                sci_base_state_machine_change_state(sm, SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD);

                /* The remote node context must cleanup the TCi to NCQ mapping
                 * table.  The only way to do this correctly is to either write
                 * to the TLCR register or to invalidate and repost the RNC. In
                 * either case the remote node context state machine will take
                 * the correct action when the remote node context is suspended
                 * and later resumed.
                 */
                scic_sds_remote_node_context_suspend(&sci_dev->rnc,
                                SCI_SOFTWARE_SUSPENSION, NULL, NULL);
                scic_sds_remote_node_context_resume(&sci_dev->rnc,
                                scic_sds_remote_device_continue_request,
                                                    sci_dev);

        out:
                scic_sds_remote_device_start_request(sci_dev, sci_req, status);
                /* We need to let the controller start request handler know that
                 * it can't post TC yet. We will provide a callback function to
                 * post TC when RNC gets resumed.
                 */
                return SCI_FAILURE_RESET_DEVICE_PARTIAL_SUCCESS;
        case SCI_BASE_REMOTE_DEVICE_STATE_READY:
                status = scic_sds_port_start_io(sci_port, sci_dev, sci_req);
                if (status != SCI_SUCCESS)
                        return status;

                status = scic_sds_remote_node_context_start_task(&sci_dev->rnc, sci_req);
                if (status != SCI_SUCCESS)
                        break;

                status = scic_sds_request_start(sci_req);
                break;
        }
        scic_sds_remote_device_start_request(sci_dev, sci_req, status);

        return status;
}

/**
 *
 * @sci_dev:
 * @request:
 *
 * This method takes the request and bulids an appropriate SCU context for the
 * request and then requests the controller to post the request. none
 */
void scic_sds_remote_device_post_request(
        struct scic_sds_remote_device *sci_dev,
        u32 request)
{
        u32 context;

        context = scic_sds_remote_device_build_command_context(sci_dev, request);

        scic_sds_controller_post_request(
                scic_sds_remote_device_get_controller(sci_dev),
                context
                );
}

/* called once the remote node context has transisitioned to a
 * ready state.  This is the indication that the remote device object can also
 * transition to ready.
 */
static void remote_device_resume_done(void *_dev)
{
        struct scic_sds_remote_device *sci_dev = _dev;

        if (is_remote_device_ready(sci_dev))
                return;

        /* go 'ready' if we are not already in a ready state */
        sci_base_state_machine_change_state(&sci_dev->state_machine,
                                            SCI_BASE_REMOTE_DEVICE_STATE_READY);
}

static void scic_sds_stp_remote_device_ready_idle_substate_resume_complete_handler(void *_dev)
{
        struct scic_sds_remote_device *sci_dev = _dev;
        struct isci_remote_device *idev = sci_dev_to_idev(sci_dev);
        struct scic_sds_controller *scic = sci_dev->owning_port->owning_controller;

        /* For NCQ operation we do not issue a isci_remote_device_not_ready().
         * As a result, avoid sending the ready notification.
         */
        if (sci_dev->state_machine.previous_state_id != SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ)
                isci_remote_device_ready(scic_to_ihost(scic), idev);
}

static void scic_sds_remote_device_initial_state_enter(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;

        /* Initial state is a transitional state to the stopped state */
        sci_base_state_machine_change_state(&sci_dev->state_machine,
                                            SCI_BASE_REMOTE_DEVICE_STATE_STOPPED);
}

/**
 * scic_remote_device_destruct() - free remote node context and destruct
 * @remote_device: This parameter specifies the remote device to be destructed.
 *
 * Remote device objects are a limited resource.  As such, they must be
 * protected.  Thus calls to construct and destruct are mutually exclusive and
 * non-reentrant. The return value shall indicate if the device was
 * successfully destructed or if some failure occurred. enum sci_status This value
 * is returned if the device is successfully destructed.
 * SCI_FAILURE_INVALID_REMOTE_DEVICE This value is returned if the supplied
 * device isn't valid (e.g. it's already been destoryed, the handle isn't
 * valid, etc.).
 */
static enum sci_status scic_remote_device_destruct(struct scic_sds_remote_device *sci_dev)
{
        struct sci_base_state_machine *sm = &sci_dev->state_machine;
        enum scic_sds_remote_device_states state = sm->current_state_id;
        struct scic_sds_controller *scic;

        if (state != SCI_BASE_REMOTE_DEVICE_STATE_STOPPED) {
                dev_warn(scirdev_to_dev(sci_dev), "%s: in wrong state: %d\n",
                         __func__, state);
                return SCI_FAILURE_INVALID_STATE;
        }

        scic = sci_dev->owning_port->owning_controller;
        scic_sds_controller_free_remote_node_context(scic, sci_dev,
                                                     sci_dev->rnc.remote_node_index);
        sci_dev->rnc.remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;
        sci_base_state_machine_change_state(sm, SCI_BASE_REMOTE_DEVICE_STATE_FINAL);

        return SCI_SUCCESS;
}

/**
 * isci_remote_device_deconstruct() - This function frees an isci_remote_device.
 * @ihost: This parameter specifies the isci host object.
 * @idev: This parameter specifies the remote device to be freed.
 *
 */
static void isci_remote_device_deconstruct(struct isci_host *ihost, struct isci_remote_device *idev)
{
        dev_dbg(&ihost->pdev->dev,
                "%s: isci_device = %p\n", __func__, idev);

        /* There should not be any outstanding io's. All paths to
         * here should go through isci_remote_device_nuke_requests.
         * If we hit this condition, we will need a way to complete
         * io requests in process */
        while (!list_empty(&idev->reqs_in_process)) {

                dev_err(&ihost->pdev->dev,
                        "%s: ** request list not empty! **\n", __func__);
                BUG();
        }

        scic_remote_device_destruct(&idev->sci);
        idev->domain_dev->lldd_dev = NULL;
        idev->domain_dev = NULL;
        idev->isci_port = NULL;
        list_del_init(&idev->node);

        clear_bit(IDEV_START_PENDING, &idev->flags);
        clear_bit(IDEV_STOP_PENDING, &idev->flags);
        clear_bit(IDEV_EH, &idev->flags);
        wake_up(&ihost->eventq);
}

/**
 * isci_remote_device_stop_complete() - This function is called by the scic
 *    when the remote device stop has completed. We mark the isci device as not
 *    ready and remove the isci remote device.
 * @ihost: This parameter specifies the isci host object.
 * @idev: This parameter specifies the remote device.
 * @status: This parameter specifies status of the completion.
 *
 */
static void isci_remote_device_stop_complete(struct isci_host *ihost,
                                             struct isci_remote_device *idev)
{
        dev_dbg(&ihost->pdev->dev, "%s: complete idev = %p\n", __func__, idev);

        isci_remote_device_change_state(idev, isci_stopped);

        /* after stop, we can tear down resources. */
        isci_remote_device_deconstruct(ihost, idev);
}

static void scic_sds_remote_device_stopped_state_enter(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;
        struct scic_sds_controller *scic = sci_dev->owning_port->owning_controller;
        struct isci_remote_device *idev = sci_dev_to_idev(sci_dev);
        u32 prev_state;

        /* If we are entering from the stopping state let the SCI User know that
         * the stop operation has completed.
         */
        prev_state = sci_dev->state_machine.previous_state_id;
        if (prev_state == SCI_BASE_REMOTE_DEVICE_STATE_STOPPING)
                isci_remote_device_stop_complete(scic_to_ihost(scic), idev);

        scic_sds_controller_remote_device_stopped(scic, sci_dev);
}

static void scic_sds_remote_device_starting_state_enter(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;
        struct scic_sds_controller *scic = scic_sds_remote_device_get_controller(sci_dev);
        struct isci_host *ihost = scic_to_ihost(scic);
        struct isci_remote_device *idev = sci_dev_to_idev(sci_dev);

        isci_remote_device_not_ready(ihost, idev,
                                     SCIC_REMOTE_DEVICE_NOT_READY_START_REQUESTED);
}

static void scic_sds_remote_device_ready_state_enter(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;
        struct scic_sds_controller *scic = sci_dev->owning_port->owning_controller;
        struct isci_remote_device *idev = sci_dev_to_idev(sci_dev);
        struct domain_device *dev = idev->domain_dev;

        scic->remote_device_sequence[sci_dev->rnc.remote_node_index]++;

        if (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_SATA)) {
                sci_base_state_machine_change_state(&sci_dev->state_machine,
                                                    SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE);
        } else if (dev_is_expander(dev)) {
                sci_base_state_machine_change_state(&sci_dev->state_machine,
                                                    SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE);
        } else
                isci_remote_device_ready(scic_to_ihost(scic), idev);
}

static void scic_sds_remote_device_ready_state_exit(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;
        struct domain_device *dev = sci_dev_to_domain(sci_dev);

        if (dev->dev_type == SAS_END_DEV) {
                struct scic_sds_controller *scic = sci_dev->owning_port->owning_controller;
                struct isci_remote_device *idev = sci_dev_to_idev(sci_dev);

                isci_remote_device_not_ready(scic_to_ihost(scic), idev,
                                             SCIC_REMOTE_DEVICE_NOT_READY_STOP_REQUESTED);
        }
}

static void scic_sds_remote_device_resetting_state_enter(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;

        scic_sds_remote_node_context_suspend(
                &sci_dev->rnc, SCI_SOFTWARE_SUSPENSION, NULL, NULL);
}

static void scic_sds_remote_device_resetting_state_exit(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;

        scic_sds_remote_node_context_resume(&sci_dev->rnc, NULL, NULL);
}

static void scic_sds_stp_remote_device_ready_idle_substate_enter(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;

        sci_dev->working_request = NULL;
        if (scic_sds_remote_node_context_is_ready(&sci_dev->rnc)) {
                /*
                 * Since the RNC is ready, it's alright to finish completion
                 * processing (e.g. signal the remote device is ready). */
                scic_sds_stp_remote_device_ready_idle_substate_resume_complete_handler(sci_dev);
        } else {
                scic_sds_remote_node_context_resume(&sci_dev->rnc,
                        scic_sds_stp_remote_device_ready_idle_substate_resume_complete_handler,
                        sci_dev);
        }
}

static void scic_sds_stp_remote_device_ready_cmd_substate_enter(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;
        struct scic_sds_controller *scic = scic_sds_remote_device_get_controller(sci_dev);

        BUG_ON(sci_dev->working_request == NULL);

        isci_remote_device_not_ready(scic_to_ihost(scic), sci_dev_to_idev(sci_dev),
                                     SCIC_REMOTE_DEVICE_NOT_READY_SATA_REQUEST_STARTED);
}

static void scic_sds_stp_remote_device_ready_ncq_error_substate_enter(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;
        struct scic_sds_controller *scic = scic_sds_remote_device_get_controller(sci_dev);
        struct isci_remote_device *idev = sci_dev_to_idev(sci_dev);

        if (sci_dev->not_ready_reason == SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED)
                isci_remote_device_not_ready(scic_to_ihost(scic), idev,
                                             sci_dev->not_ready_reason);
}

static void scic_sds_smp_remote_device_ready_idle_substate_enter(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;
        struct scic_sds_controller *scic = scic_sds_remote_device_get_controller(sci_dev);

        isci_remote_device_ready(scic_to_ihost(scic), sci_dev_to_idev(sci_dev));
}

static void scic_sds_smp_remote_device_ready_cmd_substate_enter(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;
        struct scic_sds_controller *scic = scic_sds_remote_device_get_controller(sci_dev);

        BUG_ON(sci_dev->working_request == NULL);

        isci_remote_device_not_ready(scic_to_ihost(scic), sci_dev_to_idev(sci_dev),
                                     SCIC_REMOTE_DEVICE_NOT_READY_SMP_REQUEST_STARTED);
}

static void scic_sds_smp_remote_device_ready_cmd_substate_exit(void *object)
{
        struct scic_sds_remote_device *sci_dev = object;

        sci_dev->working_request = NULL;
}

static const struct sci_base_state scic_sds_remote_device_state_table[] = {
        [SCI_BASE_REMOTE_DEVICE_STATE_INITIAL] = {
                .enter_state = scic_sds_remote_device_initial_state_enter,
        },
        [SCI_BASE_REMOTE_DEVICE_STATE_STOPPED] = {
                .enter_state = scic_sds_remote_device_stopped_state_enter,
        },
        [SCI_BASE_REMOTE_DEVICE_STATE_STARTING] = {
                .enter_state = scic_sds_remote_device_starting_state_enter,
        },
        [SCI_BASE_REMOTE_DEVICE_STATE_READY] = {
                .enter_state = scic_sds_remote_device_ready_state_enter,
                .exit_state  = scic_sds_remote_device_ready_state_exit
        },
        [SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE] = {
                .enter_state = scic_sds_stp_remote_device_ready_idle_substate_enter,
        },
        [SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD] = {
                .enter_state = scic_sds_stp_remote_device_ready_cmd_substate_enter,
        },
        [SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ] = { },
        [SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR] = {
                .enter_state = scic_sds_stp_remote_device_ready_ncq_error_substate_enter,
        },
        [SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET] = { },
        [SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE] = {
                .enter_state = scic_sds_smp_remote_device_ready_idle_substate_enter,
        },
        [SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD] = {
                .enter_state = scic_sds_smp_remote_device_ready_cmd_substate_enter,
                .exit_state  = scic_sds_smp_remote_device_ready_cmd_substate_exit,
        },
        [SCI_BASE_REMOTE_DEVICE_STATE_STOPPING] = { },
        [SCI_BASE_REMOTE_DEVICE_STATE_FAILED] = { },
        [SCI_BASE_REMOTE_DEVICE_STATE_RESETTING] = {
                .enter_state = scic_sds_remote_device_resetting_state_enter,
                .exit_state  = scic_sds_remote_device_resetting_state_exit
        },
        [SCI_BASE_REMOTE_DEVICE_STATE_FINAL] = { },
};

/**
 * scic_remote_device_construct() - common construction
 * @sci_port: SAS/SATA port through which this device is accessed.
 * @sci_dev: remote device to construct
 *
 * This routine just performs benign initialization and does not
 * allocate the remote_node_context which is left to
 * scic_remote_device_[de]a_construct().  scic_remote_device_destruct()
 * frees the remote_node_context(s) for the device.
 */
static void scic_remote_device_construct(struct scic_sds_port *sci_port,
                                  struct scic_sds_remote_device *sci_dev)
{
        sci_dev->owning_port = sci_port;
        sci_dev->started_request_count = 0;

        sci_base_state_machine_construct(
                &sci_dev->state_machine,
                sci_dev,
                scic_sds_remote_device_state_table,
                SCI_BASE_REMOTE_DEVICE_STATE_INITIAL
                );

        sci_base_state_machine_start(
                &sci_dev->state_machine
                );

        scic_sds_remote_node_context_construct(&sci_dev->rnc,
                                               SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX);
}

/**
 * scic_remote_device_da_construct() - construct direct attached device.
 *
 * The information (e.g. IAF, Signature FIS, etc.) necessary to build
 * the device is known to the SCI Core since it is contained in the
 * scic_phy object.  Remote node context(s) is/are a global resource
 * allocated by this routine, freed by scic_remote_device_destruct().
 *
 * Returns:
 * SCI_FAILURE_DEVICE_EXISTS - device has already been constructed.
 * SCI_FAILURE_UNSUPPORTED_PROTOCOL - e.g. sas device attached to
 * sata-only controller instance.
 * SCI_FAILURE_INSUFFICIENT_RESOURCES - remote node contexts exhausted.
 */
static enum sci_status scic_remote_device_da_construct(struct scic_sds_port *sci_port,
                                                       struct scic_sds_remote_device *sci_dev)
{
        enum sci_status status;
        struct domain_device *dev = sci_dev_to_domain(sci_dev);

        scic_remote_device_construct(sci_port, sci_dev);

        /*
         * This information is request to determine how many remote node context
         * entries will be needed to store the remote node.
         */
        sci_dev->is_direct_attached = true;
        status = scic_sds_controller_allocate_remote_node_context(sci_port->owning_controller,
                                                                  sci_dev,
                                                                  &sci_dev->rnc.remote_node_index);

        if (status != SCI_SUCCESS)
                return status;

        if (dev->dev_type == SAS_END_DEV || dev->dev_type == SATA_DEV ||
            (dev->tproto & SAS_PROTOCOL_STP) || dev_is_expander(dev))
                /* pass */;
        else
                return SCI_FAILURE_UNSUPPORTED_PROTOCOL;

        sci_dev->connection_rate = scic_sds_port_get_max_allowed_speed(sci_port);

        /* / @todo Should I assign the port width by reading all of the phys on the port? */
        sci_dev->device_port_width = 1;

        return SCI_SUCCESS;
}

/**
 * scic_remote_device_ea_construct() - construct expander attached device
 *
 * Remote node context(s) is/are a global resource allocated by this
 * routine, freed by scic_remote_device_destruct().
 *
 * Returns:
 * SCI_FAILURE_DEVICE_EXISTS - device has already been constructed.
 * SCI_FAILURE_UNSUPPORTED_PROTOCOL - e.g. sas device attached to
 * sata-only controller instance.
 * SCI_FAILURE_INSUFFICIENT_RESOURCES - remote node contexts exhausted.
 */
static enum sci_status scic_remote_device_ea_construct(struct scic_sds_port *sci_port,
                                                       struct scic_sds_remote_device *sci_dev)
{
        struct domain_device *dev = sci_dev_to_domain(sci_dev);
        enum sci_status status;

        scic_remote_device_construct(sci_port, sci_dev);

        status = scic_sds_controller_allocate_remote_node_context(sci_port->owning_controller,
                                                                  sci_dev,
                                                                  &sci_dev->rnc.remote_node_index);
        if (status != SCI_SUCCESS)
                return status;

        if (dev->dev_type == SAS_END_DEV || dev->dev_type == SATA_DEV ||
            (dev->tproto & SAS_PROTOCOL_STP) || dev_is_expander(dev))
                /* pass */;
        else
                return SCI_FAILURE_UNSUPPORTED_PROTOCOL;

        /*
         * For SAS-2 the physical link rate is actually a logical link
         * rate that incorporates multiplexing.  The SCU doesn't
         * incorporate multiplexing and for the purposes of the
         * connection the logical link rate is that same as the
         * physical.  Furthermore, the SAS-2 and SAS-1.1 fields overlay
         * one another, so this code works for both situations. */
        sci_dev->connection_rate = min_t(u16, scic_sds_port_get_max_allowed_speed(sci_port),
                                         dev->linkrate);

        /* / @todo Should I assign the port width by reading all of the phys on the port? */
        sci_dev->device_port_width = 1;

        return SCI_SUCCESS;
}

/**
 * scic_remote_device_start() - This method will start the supplied remote
 *    device.  This method enables normal IO requests to flow through to the
 *    remote device.
 * @remote_device: This parameter specifies the device to be started.
 * @timeout: This parameter specifies the number of milliseconds in which the
 *    start operation should complete.
 *
 * An indication of whether the device was successfully started. SCI_SUCCESS
 * This value is returned if the device was successfully started.
 * SCI_FAILURE_INVALID_PHY This value is returned if the user attempts to start
 * the device when there have been no phys added to it.
 */
static enum sci_status scic_remote_device_start(struct scic_sds_remote_device *sci_dev,
                                                u32 timeout)
{
        struct sci_base_state_machine *sm = &sci_dev->state_machine;
        enum scic_sds_remote_device_states state = sm->current_state_id;
        enum sci_status status;

        if (state != SCI_BASE_REMOTE_DEVICE_STATE_STOPPED) {
                dev_warn(scirdev_to_dev(sci_dev), "%s: in wrong state: %d\n",
                         __func__, state);
                return SCI_FAILURE_INVALID_STATE;
        }

        status = scic_sds_remote_node_context_resume(&sci_dev->rnc,
                                                     remote_device_resume_done,
                                                     sci_dev);
        if (status != SCI_SUCCESS)
                return status;

        sci_base_state_machine_change_state(sm, SCI_BASE_REMOTE_DEVICE_STATE_STARTING);

        return SCI_SUCCESS;
}

static enum sci_status isci_remote_device_construct(struct isci_port *iport,
                                                    struct isci_remote_device *idev)
{
        struct scic_sds_port *sci_port = &iport->sci;
        struct isci_host *ihost = iport->isci_host;
        struct domain_device *dev = idev->domain_dev;
        enum sci_status status;

        if (dev->parent && dev_is_expander(dev->parent))
                status = scic_remote_device_ea_construct(sci_port, &idev->sci);
        else
                status = scic_remote_device_da_construct(sci_port, &idev->sci);

        if (status != SCI_SUCCESS) {
                dev_dbg(&ihost->pdev->dev, "%s: construct failed: %d\n",
                        __func__, status);

                return status;
        }

        /* start the device. */
        status = scic_remote_device_start(&idev->sci, ISCI_REMOTE_DEVICE_START_TIMEOUT);

        if (status != SCI_SUCCESS)
                dev_warn(&ihost->pdev->dev, "remote device start failed: %d\n",
                         status);

        return status;
}

void isci_remote_device_nuke_requests(struct isci_host *ihost, struct isci_remote_device *idev)
{
        DECLARE_COMPLETION_ONSTACK(aborted_task_completion);

        dev_dbg(&ihost->pdev->dev,
                "%s: idev = %p\n", __func__, idev);

        /* Cleanup all requests pending for this device. */
        isci_terminate_pending_requests(ihost, idev, terminating);

        dev_dbg(&ihost->pdev->dev,
                "%s: idev = %p, done\n", __func__, idev);
}

/**
 * This function builds the isci_remote_device when a libsas dev_found message
 *    is received.
 * @isci_host: This parameter specifies the isci host object.
 * @port: This parameter specifies the isci_port conected to this device.
 *
 * pointer to new isci_remote_device.
 */
static struct isci_remote_device *
isci_remote_device_alloc(struct isci_host *ihost, struct isci_port *iport)
{
        struct isci_remote_device *idev;
        int i;

        for (i = 0; i < SCI_MAX_REMOTE_DEVICES; i++) {
                idev = &ihost->devices[i];
                if (!test_and_set_bit(IDEV_ALLOCATED, &idev->flags))
                        break;
        }

        if (i >= SCI_MAX_REMOTE_DEVICES) {
                dev_warn(&ihost->pdev->dev, "%s: failed\n", __func__);
                return NULL;
        }

        if (WARN_ONCE(!list_empty(&idev->reqs_in_process), "found requests in process\n"))
                return NULL;

        if (WARN_ONCE(!list_empty(&idev->node), "found non-idle remote device\n"))
                return NULL;

        isci_remote_device_change_state(idev, isci_freed);

        return idev;
}

/**
 * isci_remote_device_stop() - This function is called internally to stop the
 *    remote device.
 * @isci_host: This parameter specifies the isci host object.
 * @isci_device: This parameter specifies the remote device.
 *
 * The status of the scic request to stop.
 */
enum sci_status isci_remote_device_stop(struct isci_host *ihost, struct isci_remote_device *idev)
{
        enum sci_status status;
        unsigned long flags;

        dev_dbg(&ihost->pdev->dev,
                "%s: isci_device = %p\n", __func__, idev);

        isci_remote_device_change_state(idev, isci_stopping);

        /* Kill all outstanding requests. */
        isci_remote_device_nuke_requests(ihost, idev);

        set_bit(IDEV_STOP_PENDING, &idev->flags);

        spin_lock_irqsave(&ihost->scic_lock, flags);
        status = scic_remote_device_stop(&idev->sci, 50);
        spin_unlock_irqrestore(&ihost->scic_lock, flags);

        /* Wait for the stop complete callback. */
        if (status == SCI_SUCCESS) {
                wait_for_device_stop(ihost, idev);
                clear_bit(IDEV_ALLOCATED, &idev->flags);
        }

        dev_dbg(&ihost->pdev->dev,
                "%s: idev = %p - after completion wait\n",
                __func__, idev);

        return status;
}

/**
 * isci_remote_device_gone() - This function is called by libsas when a domain
 *    device is removed.
 * @domain_device: This parameter specifies the libsas domain device.
 *
 */
void isci_remote_device_gone(struct domain_device *dev)
{
        struct isci_host *ihost = dev_to_ihost(dev);
        struct isci_remote_device *idev = dev->lldd_dev;

        dev_dbg(&ihost->pdev->dev,
                "%s: domain_device = %p, isci_device = %p, isci_port = %p\n",
                __func__, dev, idev, idev->isci_port);

        isci_remote_device_stop(ihost, idev);
}


/**
 * isci_remote_device_found() - This function is called by libsas when a remote
 *    device is discovered. A remote device object is created and started. the
 *    function then sleeps until the sci core device started message is
 *    received.
 * @domain_device: This parameter specifies the libsas domain device.
 *
 * status, zero indicates success.
 */
int isci_remote_device_found(struct domain_device *domain_dev)
{
        struct isci_host *isci_host = dev_to_ihost(domain_dev);
        struct isci_port *isci_port;
        struct isci_phy *isci_phy;
        struct asd_sas_port *sas_port;
        struct asd_sas_phy *sas_phy;
        struct isci_remote_device *isci_device;
        enum sci_status status;

        dev_dbg(&isci_host->pdev->dev,
                "%s: domain_device = %p\n", __func__, domain_dev);

        wait_for_start(isci_host);

        sas_port = domain_dev->port;
        sas_phy = list_first_entry(&sas_port->phy_list, struct asd_sas_phy,
                                   port_phy_el);
        isci_phy = to_isci_phy(sas_phy);
        isci_port = isci_phy->isci_port;

        /* we are being called for a device on this port,
         * so it has to come up eventually
         */
        wait_for_completion(&isci_port->start_complete);

        if ((isci_stopping == isci_port_get_state(isci_port)) ||
            (isci_stopped == isci_port_get_state(isci_port)))
                return -ENODEV;

        isci_device = isci_remote_device_alloc(isci_host, isci_port);
        if (!isci_device)
                return -ENODEV;

        INIT_LIST_HEAD(&isci_device->node);
        domain_dev->lldd_dev = isci_device;
        isci_device->domain_dev = domain_dev;
        isci_device->isci_port = isci_port;
        isci_remote_device_change_state(isci_device, isci_starting);


        spin_lock_irq(&isci_host->scic_lock);
        list_add_tail(&isci_device->node, &isci_port->remote_dev_list);

        set_bit(IDEV_START_PENDING, &isci_device->flags);
        status = isci_remote_device_construct(isci_port, isci_device);
        spin_unlock_irq(&isci_host->scic_lock);

        dev_dbg(&isci_host->pdev->dev,
                "%s: isci_device = %p\n",
                __func__, isci_device);

        if (status != SCI_SUCCESS) {

                spin_lock_irq(&isci_host->scic_lock);
                isci_remote_device_deconstruct(
                        isci_host,
                        isci_device
                        );
                spin_unlock_irq(&isci_host->scic_lock);
                return -ENODEV;
        }

        /* wait for the device ready callback. */
        wait_for_device_start(isci_host, isci_device);

        return 0;
}
/**
 * isci_device_is_reset_pending() - This function will check if there is any
 *    pending reset condition on the device.
 * @request: This parameter is the isci_device object.
 *
 * true if there is a reset pending for the device.
 */
bool isci_device_is_reset_pending(
        struct isci_host *isci_host,
        struct isci_remote_device *isci_device)
{
        struct isci_request *isci_request;
        struct isci_request *tmp_req;
        bool reset_is_pending = false;
        unsigned long flags;

        dev_dbg(&isci_host->pdev->dev,
                "%s: isci_device = %p\n", __func__, isci_device);

        spin_lock_irqsave(&isci_host->scic_lock, flags);

        /* Check for reset on all pending requests. */
        list_for_each_entry_safe(isci_request, tmp_req,
                                 &isci_device->reqs_in_process, dev_node) {
                dev_dbg(&isci_host->pdev->dev,
                        "%s: isci_device = %p request = %p\n",
                        __func__, isci_device, isci_request);

                if (isci_request->ttype == io_task) {
                        struct sas_task *task = isci_request_access_task(
                                isci_request);

                        spin_lock(&task->task_state_lock);
                        if (task->task_state_flags & SAS_TASK_NEED_DEV_RESET)
                                reset_is_pending = true;
                        spin_unlock(&task->task_state_lock);
                }
        }

        spin_unlock_irqrestore(&isci_host->scic_lock, flags);

        dev_dbg(&isci_host->pdev->dev,
                "%s: isci_device = %p reset_is_pending = %d\n",
                __func__, isci_device, reset_is_pending);

        return reset_is_pending;
}

/**
 * isci_device_clear_reset_pending() - This function will clear if any pending
 *    reset condition flags on the device.
 * @request: This parameter is the isci_device object.
 *
 * true if there is a reset pending for the device.
 */
void isci_device_clear_reset_pending(struct isci_host *ihost, struct isci_remote_device *idev)
{
        struct isci_request *isci_request;
        struct isci_request *tmp_req;
        unsigned long flags = 0;

        dev_dbg(&ihost->pdev->dev, "%s: idev=%p, ihost=%p\n",
                 __func__, idev, ihost);

        spin_lock_irqsave(&ihost->scic_lock, flags);

        /* Clear reset pending on all pending requests. */
        list_for_each_entry_safe(isci_request, tmp_req,
                                 &idev->reqs_in_process, dev_node) {
                dev_dbg(&ihost->pdev->dev, "%s: idev = %p request = %p\n",
                         __func__, idev, isci_request);

                if (isci_request->ttype == io_task) {

                        unsigned long flags2;
                        struct sas_task *task = isci_request_access_task(
                                isci_request);

                        spin_lock_irqsave(&task->task_state_lock, flags2);
                        task->task_state_flags &= ~SAS_TASK_NEED_DEV_RESET;
                        spin_unlock_irqrestore(&task->task_state_lock, flags2);
                }
        }
        spin_unlock_irqrestore(&ihost->scic_lock, flags);
}